上世纪美国购银法案出台前后中国经济的变化,从正反两面验证了货币紧缩是经济萧条的重要原因。过去一个世纪里,宏观经济学的两次革命性变化都与1929-1933年的大萧条有关。1936年,凯恩斯将大萧条理解为“市场竞争体系的失败,以及货币政策无用论的明证”;1963年,弗里德曼和施瓦茨重新评论了大萧条,认为其原因在于美联储没有充当好“最后贷款 The changes of China’s economy before and after the introduction of the U.S. Purchase of Silver Act in the last century have verified from both the positive and the negative sides that the monetary tightening is an important reason for the economic depression. Over the past century, two revolutionary changes in macroeconomics have been linked to the Great Depression of 1929-1933. In 1936, Keynes interpreted the Great Depression as ”the failure of the market competition system and the proof of the useless theory of monetary policy.“ In 1963 Friedman and Schwartz reevaluated the Great Depression, arguing that the reason for the failure of the Federal Reserve Act as a good ”last loan